/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: Type.java,v 1.8 2007/03/28 16:51:19 joehw Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler.util;

import com.sun.org.apache.bcel.internal.generic.BranchInstruction;
import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;
import com.sun.org.apache.xalan.internal.xsltc.compiler.FlowList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.NodeTest;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
public abstract class Type implements Constants {

  public static final Type Int = new IntType();
  public static final Type Real = new RealType();
  public static final Type Boolean = new BooleanType();
  public static final Type NodeSet = new NodeSetType();
  public static final Type String = new StringType();
  public static final Type ResultTree = new ResultTreeType();
  public static final Type Reference = new ReferenceType();
  public static final Type Void = new VoidType();

  public static final Type Object = new ObjectType(java.lang.Object.class);
  public static final Type ObjectString = new ObjectType(java.lang.String.class);

  public static final Type Node = new NodeType(NodeTest.ANODE);
  public static final Type Root = new NodeType(NodeTest.ROOT);
  public static final Type Element = new NodeType(NodeTest.ELEMENT);
  public static final Type Attribute = new NodeType(NodeTest.ATTRIBUTE);
  public static final Type Text = new NodeType(NodeTest.TEXT);
  public static final Type Comment = new NodeType(NodeTest.COMMENT);
  public static final Type Processing_Instruction = new NodeType(NodeTest.PI);

  /**
   * Factory method to instantiate object types. Returns a pre-defined
   * instance for "java.lang.Object" and "java.lang.String".
   */
  public static Type newObjectType(String javaClassName) {
    if (javaClassName == "java.lang.Object") {
      return Type.Object;
    } else if (javaClassName == "java.lang.String") {
      return Type.ObjectString;
    } else {
      //
      java.security.AccessControlContext acc = java.security.AccessController.getContext();
      acc.checkPermission(new RuntimePermission("getContextClassLoader"));
      return new ObjectType(javaClassName);
    }
  }

  /**
   * Factory method to instantiate object types. Returns a pre-defined
   * instance for java.lang.Object.class and java.lang.String.class.
   */
  public static Type newObjectType(Class clazz) {
    if (clazz == java.lang.Object.class) {
      return Type.Object;
    } else if (clazz == java.lang.String.class) {
      return Type.ObjectString;
    } else {
      return new ObjectType(clazz);
    }
  }

  /**
   * Returns a string representation of this type.
   */
  public abstract String toString();

  /**
   * Returns true if this and other are identical types.
   */
  public abstract boolean identicalTo(Type other);

  /**
   * Returns true if this type is a numeric type. Redefined in NumberType.
   */
  public boolean isNumber() {
    return false;
  }

  /**
   * Returns true if this type has no object representaion. Redefined in
   * ResultTreeType.
   */
  public boolean implementedAsMethod() {
    return false;
  }

  /**
   * Returns true if this type is a simple type. Redefined in NumberType,
   * BooleanType and StringType.
   */
  public boolean isSimple() {
    return false;
  }

  public abstract com.sun.org.apache.bcel.internal.generic.Type toJCType();

  /**
   * Returns the distance between two types. This measure is used to select
   * overloaded functions/operators. This method is typically redefined by
   * the subclasses.
   */
  public int distanceTo(Type type) {
    return type == this ? 0 : Integer.MAX_VALUE;
  }

  /**
   * Returns the signature of an internal type's external representation.
   */
  public abstract String toSignature();

  /**
   * Translates an object of this type to an object of type
   * <code>type</code>.
   * Expects an object of the former type and pushes an object of the latter.
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Type type) {
    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
        toString(), type.toString());
    classGen.getParser().reportError(Constants.FATAL, err);
  }

  /**
   * Translates object of this type to an object of type <code>type</code>.
   * Expects an object of the former type and pushes an object of the latter
   * if not boolean. If type <code>type</code> is boolean then a branchhandle
   * list (to be appended to the false list) is returned.
   */
  public FlowList translateToDesynthesized(ClassGenerator classGen,
      MethodGenerator methodGen,
      Type type) {
    FlowList fl = null;
    if (type == Type.Boolean) {
      fl = translateToDesynthesized(classGen, methodGen,
          (BooleanType) type);
    } else {
      translateTo(classGen, methodGen, type);
    }
    return fl;
  }

  /**
   * Translates an object of this type to an non-synthesized boolean. It
   * does not push a 0 or a 1 but instead returns branchhandle list to be
   * appended to the false list.
   */
  public FlowList translateToDesynthesized(ClassGenerator classGen,
      MethodGenerator methodGen,
      BooleanType type) {
    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
        toString(), type.toString());
    classGen.getParser().reportError(Constants.FATAL, err);
    return null;
  }

  /**
   * Translates an object of this type to the external (Java) type denoted
   * by <code>clazz</code>. This method is used to translate parameters
   * when external functions are called.
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Class clazz) {
    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
        toString(), clazz.getClass().toString());
    classGen.getParser().reportError(Constants.FATAL, err);
  }

  /**
   * Translates an external (Java) type denoted by <code>clazz</code> to
   * an object of this type. This method is used to translate return values
   * when external functions are called.
   */
  public void translateFrom(ClassGenerator classGen, MethodGenerator methodGen,
      Class clazz) {
    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
        clazz.getClass().toString(), toString());
    classGen.getParser().reportError(Constants.FATAL, err);
  }

  /**
   * Translates an object of this type to its boxed representation.
   */
  public void translateBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
        toString(), "[" + toString() + "]");
    classGen.getParser().reportError(Constants.FATAL, err);
  }

  /**
   * Translates an object of this type to its unboxed representation.
   */
  public void translateUnBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
        "[" + toString() + "]", toString());
    classGen.getParser().reportError(Constants.FATAL, err);
  }

  /**
   * Returns the class name of an internal type's external representation.
   */
  public String getClassName() {
    return (EMPTYSTRING);
  }

  public Instruction ADD() {
    return null;            // should never be called
  }

  public Instruction SUB() {
    return null;            // should never be called
  }

  public Instruction MUL() {
    return null;            // should never be called
  }

  public Instruction DIV() {
    return null;            // should never be called
  }

  public Instruction REM() {
    return null;            // should never be called
  }

  public Instruction NEG() {
    return null;            // should never be called
  }

  public Instruction LOAD(int slot) {
    return null;            // should never be called
  }

  public Instruction STORE(int slot) {
    return null;            // should never be called
  }

  public Instruction POP() {
    return POP;
  }

  public BranchInstruction GT(boolean tozero) {
    return null;            // should never be called
  }

  public BranchInstruction GE(boolean tozero) {
    return null;            // should never be called
  }

  public BranchInstruction LT(boolean tozero) {
    return null;            // should never be called
  }

  public BranchInstruction LE(boolean tozero) {
    return null;            // should never be called
  }

  public Instruction CMP(boolean less) {
    return null;            // should never be called
  }

  public Instruction DUP() {
    return DUP;     // default
  }
}
